Antifriction device



Nov. 22, 1932. c. H. M. BULL ANTIFRIGTION DEVICE Filed Dec. 27. 1927 5 .m. m 8 ML A TTORNEY Patented Nov. 22, 1932 UNITED STATES ATE T oF- I C 4 CLINTON n. M. BULL, or HOUSTON, TEXAS, AssIeNoa'ro REED ROLLER B COMPANY,

or HOUSTON, TEXAS, A CORPORATION or TEXAS ANtrna'nIc'rIoN DEVICE Application filed December 27, 1927. Serial No. 242,921.

This invention relates to deep well drilling apparatus, and more particularly to drill V stem anti-friction devices.

The usual drill stem comprises a number 5 of pipe sections connected together by tool joint couplings. During drilling operations, the stem moves laterally intocontact with the sides of the hole, because of loose joints, bent portions, or the like, and such movement results in objectionable wear. As the stem is removed from the hole by pipe sec tions, the driller taps each section to discover worn portions Badly worn pipe sections are discarded and new pipe sections used in the place thereof.

This invent-ion has for one of its objects the provision of a new and improved anti-friction device embodying means whereby it may be held in place on any part of a drill stem, to

prevent wear thereof, and to prevent practical resistance to the rotation thereof.

A more specific object is to provide an anti-friction device comprising separable bearing sections, and means whereby any number of said sections may be grouped together on a drill stem.

Other objects will hereinafter appear.

In the accompanying drawing, which is illustrative of the preferred embodiment of the invention, Fig. 1 is a fragmentary side elevation of a drill stem with the anti-friction device thereon, the device being shown in section; Fig. 2, a section on the line 2-2 of Fig. 1; Fig. 3, a detail sectional elevation of the bushing; Fig. 4, a detail side elevation of the inner sleeve of a retaining device; and

Fig. 5, a detail sectional elevation of the outer sleeve of a retaining device.

The anti-friction device includes bearing elements comprising bushing 2, collar 3, and balls 4 therebetween, the collar 3 having internal annular raceways for said balls. The bushing 2, as shown, comprises two sections, and the collar 3, four sections. It is to be understood, however, that as many of these i: I

in place by a suitable ring 8. The gripping teeth on the one of said plugs is disposed of at substantially right angles to the gripping teeth on the other, so that the sleeve 5is locked against movement longitudinally of said pipe and around said pipe.

The external surface of, sleeve 5 adjacent its plug openings is tapered as shown at 5a, and the inner surface of sleeve 6 is tapered as shown I at 6a. When the outer sleeve 6 is screwed on the inner sleeve 5, the surface 6a comes in contact with the plugs 7, said plugs being thereby forced into gripping engagement with the drill stem 1.

The sleeve 5 and bushing 2 are provided? with interfitting 111 relative rotation thereof.

If desired, gaskets 9 may be interposed between collar 3 and sleeves 5 and6.

As above pointed out, the bushing2 and collar 3 may comprise any number of separable sections to cover any portion of the stem. 'The sections of the collar are independently revoluble, so that should one become locked on and rotate with the drill stem, the other or others will remain stationary while the drill stem rotates therein; and should anyone become worn, a new one may be used in its place, the other original sections being used-with the new.

By means of assembly comprising the sleeves 5 and 6 and plugs 7 the bearing elements may be held on any portion of the drill stem.

The invention is not limited to the preferred embodiment shown. Various changes may be made within the scope of the following claim.

gs 5b and 2a to prevent I claim: a The combination with a drill pipe of an anti-friction device having a pair of pipe gripping elements, each of said elements comprising an inner and an outer sleeve, said inner sleeve having a radial opening therein and said outer sleeve having a tapered portion adjacent said opening, and a pipe gripping plug movable in said opening and actuated by said portion when said sleeves are moved With respect to each other;:abushing between said elements; a plurality of collar sections on said bushing, said collar sections being revoluble independently of each other;

and balls between each of said sections and said bushing.

CLINTON H. BULL. a 

